Potentially dangerous reactions were also seen in people taking herbal treatments alongside antidepressants and those cancer therapies.

Many people take herbal remedies alongside prescribed medication

The researchers also found that many patients lied about their use of herbal medicines to the doctors, leaving specialists in the dark about potential drug interactions.

“Intake of herbal medicines and prescribed medications is a common practice especially in patients with hypertension, diabetes, cancer, seizures and depression,” said lead author Dr Charles Awortwe.

“Assessment and subsequent mechanistic studies of herbs with clinically relevant herbal drug interactions must be publicized to alert both clinicians and patients about the need to avoid co-usage of certain herbal medicines with specific prescribed medications.”

CORRECTION: This article originally stated​ ​that Professor Edzard Ernst​,​ professor of complementary medicine at Exeter Universit​y, ​had said there​ was​ 'potential for harm' ​in herbal remedies and ​that doctors were ‘contributing to disinformation’ by turning a blind eye to ​this.​ These comments did not in fact relate to ​interactions between herbal remedies​ and prescribed medication, and they have been removed. We apologise to the Professor for the error.